1311661 has 8 divisors (see below), whose sum is σ = 1423520. Its totient is φ = 1201392.

The previous prime is 1311643. The next prime is 1311689. The reversal of 1311661 is 1661131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1311661 - 2¹³ = 1303469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1810 + ... + 2428.

It is an arithmetic number, because the mean of its divisors is an integer number (177940).

2^1311661 is an apocalyptic number.

It is an amenable number.

1311661 is a deficient number, since it is larger than the sum of its proper divisors (111859).

1311661 is a wasteful number, since it uses less digits than its factorization.

1311661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795.

The product of its digits is 108, while the sum is 19.

The square root of 1311661 is about 1145.2776955830. The cubic root of 1311661 is about 109.4646438954.

Adding to 1311661 its reverse (1661131), we get a palindrome (2972792).

The spelling of 1311661 in words is "one million, three hundred eleven thousand, six hundred sixty-one".